• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.99-105
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• 1994

Most of the companies are forced to cut down the manufacturing cost to survive in the competitive environment. Among others, material distribution cost alone takes substantial portion of the total manufacturing cost. In this study, we investigate the waiting phenomenon in the toll gate and propose a new toll booth layout to reduce the waiting time, thereby reduce the total material distribution cost. SIMAN, a simulation language, is employed to evaluate the proposed layout. The experimental results show that the layout reduces the waiting time significantly. Furthermore, the result indicates that determination of the intermediate buffer space affects the performance of the proposed layout.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.1923-1931
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• 2004

Manufacturing of complex surface plates in stern and stem is a major factor in cost of a preliminary ship design by computing process. If these hull plate parts are effectively classified, it helps to compute the processing cost and find the way to cut-down the processing cost. This paper presents a new method to classify surface plates effectively in the preliminary ship design using neural network. A neural-network-based ship hull plate classification program was developed and tested for the automatic classification of ship design. The input variables are regarded as Gaussian curvature distributions on the plate. Various applicable rules of network topology are applied in the ship design. In automation of hull plate classification, two different numbers of input variables are used. By observing the results of the proposed method, the effectiveness of the proposed method is discussed. As a result, high prediction rate was achieved in the ship design. Accordingly, to the initial design stage, the ship hull plate classification program can be used to predict the ship production cost. And the proposed method will contribute to reduce the production cost of ship.

• 한국디지털정책학회:학술대회논문집
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• 2006.12a
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• pp.409-418
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• 2006

The purpose of this paper is to present a low cost u-City portal development idea and to propose an exclusive system architecture using 3-D interface layers. 3-D interface layers consist of reused ideas of data from existed public data produced from GIS in order to reduce Produce Processes. 3-D interface layers implement a u-City portal systems that tags from physical spaces 1 ink to mobiles from ubiquitous networks between electronic spaces and physical spaces. Primary produce of this study exhibits an exclusive architecture of a u-City portal for speedy and low cost web 3-D interface layers and GIS data, and for implementation interface of 3-D types on USN of physical spaces. Secondary produce of this study represents that a 3-D u-City portal system has visualized speedy implementation characteristics for implementation of the application systems to execute an ubiquitous concept by returning electronic space to physical space, and to present the low cost 3-D u-City portal than an existed 3-D u-city development strategy. Therefore continuous expansion and study of the 3-D interface physical space under a 상황인지(Context Awareness)ubiquitous will appear the innovated u-City portal systems.

• IE interfaces
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• v.12 no.1
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• pp.10-18
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• 1999

Job shop manufacturing environments are using the concept of cellular manufacturing systems(CMS) which has several advantages in reducing production lead times, setup times, work-in-process, etc. Utilizing the similarities between cell-machine, part-machine, and the shape/size of parts, CMS can group machines and parts resulting in improved efficiency of this system. However, when grouping machines and parts in machine cells, there inevitably occurs exceptional elements(EEs), which can not operate in the same machine cell. Minimizing these EEs in CMS is a critical point that improving production efficiency. Constraints in machine duplication cost, machining process technology, machining capability, and factory space limitations are main problems that prevent achiving the goal of maintaining an ideal CMS environment. This paper presents an algorithm that minimizes EEs under the constraints of machine duplication cost and factory space limitation. Developing exceptional operation similarity(EOS) by cell-machine incidence matrix and part-machine incidence matrix, it brings the machine cells that operate the parts or not. A mathematical model to minimize machine duplication is developed by EOS, followed by a heuristic algorithm in order to reflect dynamic situation resulting from minimizing exceptional elements process and the mathematical model. A numerical example is provided to illustrate the algorithm.

• Magazine of korean Tunnelling and Underground Space Association
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• v.22 no.1
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• pp.26-35
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• 2020

Tunnelling to bypass major landslide areas is considered as a good and long-term environmentally friendly solution to reduce an existing hazard. In Norway, hundreds of kilometres of tunnels have been constructed in areas prone to landslides and snow avalanches. Although tunnelling is considered as an expensive mitigation strategy for bypassing landslides, analysis indicate that in some cases the cost of building a tunnel can be repaid by savings in driving costs (fuel) alone over a period of 5-10 years due to reduced driving distances. The other benefits of constructing tunnels in landslide areas include savings in time and increased safety. The Norwegian Method of Tunnelling (NMT) is considered safe, efficient and cost effective compared to other tunnelling techniques. Some aspects of NMT, which are considered safe and cost efficient, are presented. The application of updated rock support techniques, including reinforced ribs of shotctrete (RRS), which is a key component of the Norwegian Method of Tunnelling (NMT), is highlighted.

• International Journal of Aeronautical and Space Sciences
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• v.9 no.1
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• pp.147-161
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• 2008

In this paper, fine attitude estimation using low-cost sensors for attitude pointing missions of spacecraft is addressed. Attitude kinematics and gyro models including bias models are in general utilized to estimate spacecraft attitude and angular rate. However, a linearized model and a transition matrix are derived in this paper from nonlinear spacecraft dynamics with external disturbances. A Kalman filtering technique is applied and offers relatively high estimation accuracy under dynamic uncertainties. The proposed approach is demonstrated using numerical simulations.

• Journal of Sensor Science and Technology
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• v.30 no.5
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• pp.290-294
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• 2021

Experts have designed popular and successful model architectures, which, however, were not the optimal option for different scenarios. Despite the remarkable performances achieved by deep neural networks, manually designed networks for classification tasks are the backbone of object detection. One major challenge is the ImageNet pre-training of the search space representation; moreover, the searched network incurs huge computational cost. Therefore, to overcome the obstacle of the pre-training process, we introduce a network adaptation technique using a pre-trained backbone model tested on ImageNet. The adaptation method can efficiently adapt the manually designed network on ImageNet to the new object-detection task. Neural architecture search (NAS) is adopted to adapt the architecture of the network. The adaptation is conducted on the MobileNetV2 network. The proposed NAS is tested using SSDLite detector. The results demonstrate increased performance compared to existing network architecture in terms of search cost, total number of adder arithmetics (Madds), and mean Average Precision(mAP). The total computational cost of the proposed NAS is much less than that of the State Of The Art (SOTA) NAS method.

• International Journal of Computer Science & Network Security
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• v.24 no.1
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• pp.17-22
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• 2024

The objective of this work is to design a low cost yet fully functional 4-DOF articulate manipulator for educational applications. The design is based on general purpose, programmable smart servo motors namely the Dynamixel Ax-12. The mechanism for motion was developed by formulating the equations of kinematics and subsequent solutions for joint space variables. The trajectory of end-effector in joint variable space was determined by interpolation of a 3rd order polynomial. The solutions were verified through computer simulations and ultimately implemented on the hardware. Owing to the feedback from the built-in sensors, it is possible to correct the positioning error due to loading effects. The proposed solution offers an efficient and cost-effective platform to study the trajectory planning as well as dynamics of the manipulator.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.3
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• pp.205-211
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• 2012

Unlike the previous approaches, we analyzed for economic efficiency of renewed heating and cooling systems as the characteristics of space. The purpose of this study is to analysis the energy consumption and economical efficiency of absorption chillers and EHP systems in renovated library. It is important that equipment selection should be considering energy cost as well as space program. In recently, many EHP systems were installed in the building for reducing the energy cost and for seeking the convenience of individual control. In contrast, though absorption chillers have the disadvantage of a central control, absorption chillers are appropriate for the conditions of the library that needs simultaneous operation. The results by payback period method, show that selection of heating and cooling systems should be consider for space program and the characteristics of space.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.7
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• pp.558-565
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• 2017

Recently, there has been a tendency to lead the private sector in the launch vehicle market, and as the market has become saturated, efforts are being made to reduce the launch cost. Advanced countries in space development have promoted manned long-range space exploration plans. As oxygen/methane is more efficient, lower cost, and eco-friendly than typical propellants, and can be produced locally on an alien planet, it is the most suitable next-generation propellant to meet this trend. Now methane engine development is accelerating due to changes in international conditions and corporate environment. It is also expected to develop a methane engine in order to survive in this global trend and to keep up with the launch vehicle market in the future.